The present invention relates to X-ray fluorescence analyzers.
In a system configuration shown in FIG. 9 a system controller 28, under control of an operating section 29, is controlled by, an operator to conventionally set each measuring point by moving a sample table 24 loaded with a sample by aligning crisscross lines on a sample observation monitor 27 with a desired part of the sample. When the sample to be measured is extremely small, an optical observation system such as a mirror 25, a receiver 26 and a display unit 27 having low magnifying power is usually used to observe a large area. This would, however, make it difficult to accomplish alignment on a sample monitor. One approach to this problem has been to employ an observation system switchable to a high magnification optical system. An alternative approach has been to measure the sample by using a scanning technique in which the sample is scanned in a lattice pattern with scanning intervals that are sufficiently narrow with respect to the dimensions of the sample, an operator determines the center of the sample from resultant two-dimensional profiles, and adopts measurement results obtained from that position.
It has been possible to achieve practically sufficient positioning by using the conventional sample monitor when samples were relatively large.
With the miniaturization of electronic components in recent years, however, it has become difficult to achieve their precise position alignment by a positioning technique using images presented on the sample monitor, due to the limits of image resolution and accuracy problems involved in aligning a target point for X-ray exposure with the crisscross lines on the sample monitor. In addition, there has been an increasing need for a precision positioning function because of significantly reduced positioning tolerances which would be required when a sample has been accidentally displaced as a result of a movement of a sample table in such a case where automatic measurements are to be performed after registering each measuring point of the sample.
On the other hand, the approach involving the switching to a high magnification optical system when it is difficult to align with the center of a sample with a low magnification optical system has a problem in that the system becomes too expensive, while the approach in which the center of the sample is determined from two-dimensional profiles has a problem in that it requires a considerable time, rendering these approaches impractical.
Accordingly, it is an object of the invention to provide means for enabling precise positioning of measuring points in a short time without using image information to overcome the aforementioned problems of the prior art.